LOL R888's and V70s etc ARE semi slicks dude. At least as we define them
And for the record, people who stagger tyres are usually crap because they don't understand the fact that a car needs BALANCED grip LOL There are times (HUGE angle usually) when you want the front tyres to slide slightly. Having a grippy tyre on front and rubbish on the back just reduces a car's potential performance for the sake of allowing the driver to not have to balance the car on turn-in.
The reason they can't keep up is that the difference between 'comfort' and 'sport' tyres in GT5 is unrealistic. No-one on comfort hards will EVER keep up with somone on 'sport's as far as I can see. Come for a skid this evening, I've been wanting to find someone who can REALLY drift on sports tyres so I can test some things like apex speeds etc. and see how big the differences are. Fancy helping out?